(164p) Poly(ionic liquid) Triblock and Pentablock Terpolymer Electrolytes for Solid-State Lithium Metal Batteries

Lithium metal anodes have attracted significant attention as candidates for next-generation batteries due to their higher energy density compared to current commercial lithium ion batteries. However, the severe liquid electrolyte-lithium reaction and uncontrollable lithium dendrite growth in lithium metal batteries results in lower cycle life, electrical shortages, and safety concerns. These issues also restrict the battery performance under desired conditions, including high-voltage charge-discharge and high-capacity cathode materials. The future of lithium metal batteries (safer, higher charge capacity, longer cycle life) will require a new solid polymer electrolyte (SPE) (as replacements to liquid electrolytes) that possesses multiple desired orthogonal properties (high ion conductivity, robust mechanical properties, high electrochemical stability, good film forming properties, etc.). Poly(ionic liquid) (PIL) block polymers possess a number of unique physiochemical properties, such as high electrochemical stability, high ionic conductivity, high mechanical strength, high chemical, and thermal stability, nonvolatility, nonflammability, and a widely tunable chemical platform, which allows for significant changes in physical properties with only subtle changes in chemistry. In particular, PIL block polymers containing more than two chemistries provide a more diverse set of continuous nanostructures (tri-continuous network morphologies) that can enable higher lithium ion conductivities. However, to date, there are limited studies exploring PIL multiblock polymers with more than two chemistries. In this study, PIL ABC triblock and ABCBA pentablock terpolymers were investigated as SPEs for lithium metal batteries. The chemical, thermal, mechanical, and electrochemical properties were examined as function of polymer chemistry and composition. Lithium metal batteries with PIL block polymers as SPEs were fabricated and their performance was evaluated.